Garbine Muguruza lived up to her billing as top seed by beating Alison Riske 6-2 6-3 at the last-16 stage of the Monterrey Open on Thursday.
The Spaniard dominated from almost the first ball and wrapped up victory against the American within an hour and 23 minutes.
Muguruza will face Ajla Tomljanovic in the quarter-finals after the Australian saw off the challenge of Russian teenager Anna Blinkova, who was beaten 6-2 5-7 6-2.
Sixth seed Ana Bogdan beat Sara Sorribes Tormo 6-2 6-3 in a match which had been suspended on Wednesday due to rain.
Danielle Collins also advanced to the last-eight stage after third seed Lesia Tsurenko withdrew with a toe injury.
Elsewhere, in Charleston, Alize Cornet came back from a set down to knock out top seed Caroline Garcia in the third round of the Volvo Car Open.
Cornet eventually prevailed 5-7 6-1 6-4 in the all-French encounter to set up a quarter-final clash with Kiki Bertens.
Related tennis links
